Java Dynamic Management Kit 3.2 Programming Guide | ||||
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![]() | ![]() | Chapter 14. M-Let, Bootstrap and Launcher Services | ![]() | ![]() |
The m-let and bootstrap class loaders implement the findLibrary() method of the ClassLoader class, to allow the loading of dynamic native libraries from a .jar file. The basic operation of the services is described in Library Loaders in Chapter 12.
The m-let and bootstrap class loaders use a temporary directory to store the library files before they are loaded into memory. The default temporary library directory depends on the operating environment.
Operating Environment | Default Temporary Library Directory |
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Solaris | installDir/SUNWconn/jaw/tmp |
Windows NT | installDir\SUNWconn\jaw\tmp |
If you want the m-let and bootstrap class loaders to use a temporary library directory other than the default, you can specify the new directory by invoking the setLibraryDirectory() method.
Example 14-11 shows how to use the setLibraryDirectory() method to change the temporary library directory. In this example, the m-let and bootstrap class loaders will store the library files in the /home/libs directory.
Example 14-11. Using setLibraryDirectory() to Change the Temporary Library Directory
mletSrv.setLibraryDirectory("/home/libs"); |
Example 14-12 shows an example hierarchy for the libraries in a .jar file.
Example 14-12. Library Hierarchy in a .jar File
/SunOS/sparc/5.7/lib/libA.so /SunOS/sparc/5.7/lib/libB.so \WindowsNT\x86\4.0\lib\B.dll |
An m-bean must invoke the System.loadLibrary() method to load a native library from a .jar file. Example 14-13 shows code for loading libraries from a .jar file.
Example 14-13. Loading a Library From a .jar File
System.loadLibrary("A"); // loads /libA.so System.loadLibrary("B"); // loads /SunOS/sparc/5.7/lib/libB.so // if the agent runs on Solaris 7 // loads \WindowsNT\x86\4.0\lib\B.dll // if the agent runs on Windows NT 4.0 |
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Bootstrap Service | ![]() | Security Manager |